why do you think its so easy to make 300 hp no matter where you are in the world because the the 335i automatically tunes to achieve this goal i pretty sure when you take a subie into the mountains it loses some power. and in the end its up to the user do want to control everything in the engine or do you want to let the ecu you some of the work i rather take full control when your running 7psi more then factory intended

Nice write up but most of this isn't relevant to the N54 which unlike your Subaru runs in an adaptive state at all times. If you add race gas to your car and it picks up timing then it's running off the knock threshold system. End of story. And I hate to break the news but all the tunes are including the stock tuning are.

This sort of sums it up from the other thread:

However the goal should to set timing so the max value at any given rpm is below the knock threshold. you should only rely on the knock sensor to pull timing in bad conditions not everytime you floor the car.

Definitely a great write up... But I have a question there is a spot on the table where timing goes up then down(top left shaded in red)Why is this and what causes it?

I can also show you timing maps where timing goes down steadily as rpm rises. In that case it is due to the fact that the timing pickup is on the camshaft not crankshaft. Typically where timing is picked up on the crankshaft ( more accurate ) the timing will rise initially then drop to its lowest point at max torque and steadily climb as rpms increase ( torque drops ).

Air fuel and ignition control how can you tune with out a car taking care of all three and if im correct thats what some tunes are missing ignition control
dont flame just learning as much as possible on the platform

This is just another disguised tuner bash. For whom may be interested, I have done some testing on a private road a few days ago with a friend's car which has a JB4 (he used Map 7). I have GIAC Stage 2.

The ignition timing was almost identical between my GIAC Stage 2 pump and his JB4 map 7. We compared the excel files in detail after the runs, we did graphs. Nevertheless he beat me but I have fewer mods I will ask for his permission to post some of the graphs.

Conclusion: the N54 ECU is not a Subaru ECU: it is more advanced. The knock sensors and knock ADAPTATION work very closely to ensure proper timing. At least from what I have seen, and I have seen hard data with back to back runs, not just talking and bashing.

I'm just sharing my experiences, was not intended as a "tuner bash", but I suppose I can't help how you take it.

Quote:

Originally Posted by tscdennab

In fact, it's the other way around. Subarus have predefined maps which means they make the same power even when the conditions vary (to a certain degree, of course). N54 is more dynamic and calculates many of the values "on the fly", whereas other ECUs have predefined values. That's why some days you feel the car a bit slow, some days you feel it is a beast.

No offense, but you might be a little bit outside of your knowledge base here... from what I understand, the fueling on the N54 is closed loop (WBO2 sensors from the factory FTW!! Many cars only have narrow-band O2's and can't see actual AFR outside of a small range), but just like any other modern turbo car, there are timing tables that calculate base timing in regards to load.

Subaru's actually do have compensation tables for temperature, barometric pressure (helps with elevation), knock, ect. Technically, they have what is referred to a IAM (Ignition Advance Multiplier), which is a fairly simple algorithm that when knock is sensed at XX rpm under XX load, it lowers timing (initial value of 1, shows fractional/decimal value when unable to reach peak/base timing value), and as you go through cycles, it will slowly attempt to ramp timing timing back up to base initial value. Basically, it keeps track of historic knock at various load sites, and attempts to advance timing slowly... it's remarkably similar to the autotuning feature (except with timing only, vs. boost) this community is used to, except stock.

It's kind of funny, years ago, Shiv found a way to "trick" their ECU's into raising the IAM value to its maximum in a matter of seconds haha:

Either way, in certain aspects I would agree with you, this ECU/DME is faster, able to react more quickly to knock and fueling is fully closed loop (awesome!), but when it comes to timing, I respectfully disagree, as Subaru's & EVO's employ learning curves (again, similar to autotuning in regards to timing) that keep track of historic knock and calculate accordingly.

This is just another disguised tuner bash. For whom may be interested, I have done some testing on a private road a few days ago with a friend's car which has a JB4 (he used Map 7). I have GIAC Stage 2.

The ignition timing was almost identical between my GIAC Stage 2 pump and his JB4 map 7. We compared the excel files in detail after the runs, we did graphs. Nevertheless he beat me but I have fewer mods I will ask for his permission to post some of the graphs.

Conclusion: the N54 ECU is not a Subaru ECU: it is more advanced. The knock sensors and knock ADAPTATION work very closely to ensure proper timing. At least from what I have seen, and I have seen hard data with back to back runs, not just talking and bashing.

This maybe true. The difference is, JB relies entirely on "riding" the knock sensor and the stock DME to adjust for anything that gets thrown at it.

Whereas, GIAC/Cobb, any other flash tuner, re-writes those ignition timing tables to take into account proactively, the additional boost/load demand, all tested on the dyno...to avoid relying on bouncing on the knock sensor and DME to "REACT".

There is a huge difference between using the knock sensor as a fail-safe/last ditch security mechanism, and RIDING it all the time and relying on it to adjust timing.

This is 101 FI tuning fundamentals. You need to control timing to avoid detonation at all costs...or engine goes boom....that simple.

But I agree, it is more a tribute to how well BMW designed/developed the stock knock system and DME logic to save its ass over and over with some tunes....

However the goal should to set timing so the max value at any given rpm is below the knock threshold. you should only rely on the knock sensor to pull timing in bad conditions not everytime you floor the car.

This^...exactly what I just wrote in the other thread and this one also.

It should be a failsafe...not the ONLY WAY of controlling and relying on timing/knock/detonation.

This is what people need to understand completely, RULE #1. It is fundamental and essential 101 FI tuning best practices by anyone who knows what they are doing.

Good post. Were the subarus you mention closed loop all of the time? Because if not, then you can't compare the two. I know the rx7s weren't, and you had to rely on user maps. These types of piggybacks would never have worked on an rx7. Just like the S-afc would not work-safely, that is. Maybe that's the reason for the confusion here?

Fueling is closed loop on these cars compared to open loop on most other cars thanks to employing WB02 sensors from the factory and having an ECU smart enough to address AFR quickly. However, there are still timing tables for these cars with base values that should be determined by load, just like any other modern turbo car (well, most NA cars as well).

Quote:

Originally Posted by Morpheus

It's also the reason you can't just slap on DPs an exhaust, and an intake and make 50hp with no tune. With an rx7 there was the 3 mod rule. Ever heard of that? Three airflow mods: intake, exhaust, downpipe. Any more than that and BOOM. Actually sometimes not, and sometimes even with less than three the engine went boom anyway. All it took was a hot day, or a bad tank of gas. Why? Because the ECU wasn't able to react. That's not the case here.

You're also incorrect in saying that the knock sensor is setting the BASE timing map. BMW sets the base ignition map and it does indeed look similar to the one you posted and does decrease timinq with load. I may be oversimplifying things here and somebody correct me If I'm wrong because I'm only repeating what I've read here, but it's my understanding that the flashes rely on the knock sensor as well, but with a 3 degree "head start".

Maybe there was a misunderstanding (we're on an open forum, it happens ), but I agree the base timing map (unless altered) is set by BMW from the factory. Sorry, I thought it was implied.

IMO, the knock sensor is meant to be a failsafe, and under the wrong circumstances it is a crucial tool in saving your motor. However, rather than relying on it as a means to altering timing, the base timing values should be set as a maximum, which should be under the knock threshold. Ultimately, the goal when tuning should be be set timing values (as well as AFR & boost of course) to a value that allows WOT operation without knock under most normal conditions.

Quote:

Originally Posted by Clap135

However the goal should to set timing so the max value at any given rpm is below the knock threshold. you should only rely on the knock sensor to pull timing in bad conditions not everytime you floor the car.

^^^ Apparently you beat me to it

+1

While you and I see to have different styles of communication, on a technical level, we seem to have a similar mindset.

I've seen numerous OTS maps for multiple cars... I'm not a big fan, as they typically leave much to be desired. Hell, I'm not even a big fan of many supposedly conservative factory tunes (I've seen some pretty atrocious logs on stock cars of various makes over the years!! We're talking LTFT's around ~15%, AFR's deep into the 9:1 range under WOT, knock/timing correction all over, cars that won't hit peak targeted boost, you name it). Ultimately, these maps are made/tuned by someone else in another part of the country, and like humans, among cars there will always be variances. Manufacturers try to be overly conservative and make maps that will be safe in a variety of conditions, but there are so many variables from car to car that this is rarely optimum. I've seen cars with the same mods, running the same OTS maps, under the same conditions (elevation, fuel grade ect) make WOT pulls, and the logs/torque curves are vastly different.

Personally, I would rather tune my own car, for my own conditions (fuel grade, elevation, variances specific to my vehicle, ect, preferably under harsh conditions..) to ensure that my car is knock free while pushing peak boost/timing/under full load. I'm a big fan of optimum performance, consistency and safety when at all possible

Fueling is closed loop on these cars compared to open loop on most other cars thanks to employing x2 WB02 sensors from the factory and having an ECU smart enough to address AFR quickly. However, there are still timing tables for these cars with base values that should be determined by load, just like any other modern turbo car (well, most NA cars as well).

Maybe there was a misunderstanding (we're on an open forum, it happens ), but I agree the base timing map (unless altered) is set by BMW from the factory. Sorry, I thought it was implied.

IMO, the knock sensor is meant to be a failsafe, and under the wrong circumstances it is a crucial tool in saving your motor. However, rather than relying on it as a means to altering timing, the base timing values should be set as a maximum, which should be under the knock threshold. Ultimately, the goal when tuning should be be set timing values (as well as AFR & boost of course) to a value that allows WOT operation without knock under most normal conditions.

^^^ Apparently you beat me to it

+1

While you and I see to have different styles of communication, on a technical level, we seem to have a similar mindset.

I've seen numerous OTS maps for multiple cars... I'm not a big fan, as they typically leave much to be desired. Hell, I'm not even a big fan of many supposedly conservative factory tunes (I've seen some pretty atrocious logs on stock cars of various makes over the years!! We're talking LTFT's around ~15%, AFR's deep into the 9:1 range under WOT, knock/timing correction all over, cars that won't hit peak targeted boost, you name it). Ultimately, these maps are made/tuned by someone else in another part of the country, and like humans, among cars there will always be variances. Manufacturers try to be overly conservative and make maps that will be safe in a variety of conditions, but there are so many variables from car to car that this is rarely optimum. I've seen cars with the same mods, running the same OTS maps, under the same conditions (elevation, fuel grade ect) make WOT pulls, and the logs/torque curves are vastly different.

Personally, I would rather tune my own car, for my own conditions (fuel grade, elevation, variances specific to my vehicle, ect, preferably under harsh conditions..) to ensure that my car is knock free while pushing peak boost/timing/under full load. I'm a big fan of optimum performance, consistency and safety when at all possible
That's just my $.02 though, YMMV.

EXACTLY

If your riding the knock sensors 24/7 this simply isnt possible.

I had my car custom dyno tuned last summer (which didnt work at all thanks to a clogged cat that I only discovered a few weeks ago ). A few other car geeks were there and all were bummed that it was close to 110f in the shop since we wouldnt see huge #'s being thrown down.

I on the other hand was happy with the heat, it meant that my custom tune would have the ability to be safe even in the worst conditions the car will ever see.

I want a safe and reliable tune that is not tuned to max power at all times, if you run an engine at 99.9% all the time and let the knock sensors pull timing back everytime you floor it, you ARE causing undue stress on your engine.

You and I def show the same understanding of how tuning should be applied. The difference that I have a low tolerance for ignorant spiteful members who know they are wrong but continue to post because they feel the need to justify their incorrect logic.

Quote:

Originally Posted by roninsoldier83

Fueling is closed loop on these cars compared to open loop on most other cars thanks to employing x2 WB02 sensors from the factory and having an ECU smart enough to address AFR quickly. However, there are still timing tables for these cars with base values that should be determined by load, just like any other modern turbo car (well, most NA cars as well).

Maybe there was a misunderstanding (we're on an open forum, it happens ), but I agree the base timing map (unless altered) is set by BMW from the factory. Sorry, I thought it was implied.

IMO, the knock sensor is meant to be a failsafe, and under the wrong circumstances it is a crucial tool in saving your motor. However, rather than relying on it as a means to altering timing, the base timing values should be set as a maximum, which should be under the knock threshold. Ultimately, the goal when tuning should be be set timing values (as well as AFR & boost of course) to a value that allows WOT operation without knock under most normal conditions.

^^^ Apparently you beat me to it

+1

While you and I see to have different styles of communication, on a technical level, we seem to have a similar mindset.

I've seen numerous OTS maps for multiple cars... I'm not a big fan, as they typically leave much to be desired. Hell, I'm not even a big fan of many supposedly conservative factory tunes (I've seen some pretty atrocious logs on stock cars of various makes over the years!! We're talking LTFT's around ~15%, AFR's deep into the 9:1 range under WOT, knock/timing correction all over, cars that won't hit peak targeted boost, you name it). Ultimately, these maps are made/tuned by someone else in another part of the country, and like humans, among cars there will always be variances. Manufacturers try to be overly conservative and make maps that will be safe in a variety of conditions, but there are so many variables from car to car that this is rarely optimum. I've seen cars with the same mods, running the same OTS maps, under the same conditions (elevation, fuel grade ect) make WOT pulls, and the logs/torque curves are vastly different.

Personally, I would rather tune my own car, for my own conditions (fuel grade, elevation, variances specific to my vehicle, ect, preferably under harsh conditions..) to ensure that my car is knock free while pushing peak boost/timing/under full load. I'm a big fan of optimum performance, consistency and safety when at all possible

It is really nice to see a few more individuals that are coming out and posting on e90 that actually understand tuning and even some who tune their own cars and help others tune as well.

Its funny because we all post the same facts and information and get opposed with illogical and uninformed opinions. Some of us do it nicely and others are just fed up with the ignorance that some people bring in.

It just simply astonishes me that people can rationalize an arguement that relying on a safety feature because it is so advanced is sufficient compared to actually tuning the car and leaving that safety feature as just that - a safety feature - back up for those conditions out of your control where knock occurs.

Different platforms require different tuning styles - STYLES. That means that each platform has different timing curves. Some heads flow better than others. Some cars can run leaner than others. That much is true (and more examples but you get the point). The one thing that every platform has in common is that safe engine tuning practices consist of tuning boost, afr, and timing and monitoring many parameters to ensure they are done properly, safely, and make power with the first characteristics in mind. Eliminating knock and monitoring EGTs, AFRs, Oil temps, etc. can really tell you alot. Monitoring for knock is crucial (and all of the above temps and values can tell you why you knocked). No tuner would let a car they are tuning leave with the customer that knocks, knocks a lot, or knocks occassionally. If they did they wouldn't get customers. It happens all the time. I can name multiple shops and tuners that went out of business because of poor timing maps and cars knocking more then once in a blue moon.

I feel like the n54 is probably the worst platform to start understanding how tuning works. All the guys who preach correct tuning have experience with other platforms that were not as near forgiving. The slightest mistake with a decent power output and bam you are out 7k rebuilding the motor. My last car was a Nazi Fuck when it came to tuning. Many of the people posting on here have witnessed me tuning my car on a weekly basis. People blew motors with intakes while I lasted 40k and set various records and eventually put the biggest turbo on the car available at the time. Am I the norm? No because I am beyond belief anal when it comes to tunning. And quite frankly if Cobb wasn't releasing atr for this car. The tuning systems available for this platform currently are a joke...

I feel like the n54 is probably the worst platform to start understanding how tuning works. All the guys who preach correct tuning have experience with other platforms that were not as near forgiving. The slightest mistake with a decent power output and bam you are out 7k rebuilding the motor. My last car was a Nazi Fuck when it came to tuning. Many of the people posting on here have witnessed me tuning my car on a weekly basis. People blew motors with intakes while I lasted 40k and set various records and eventually put the biggest turbo on the car available at the time. Am I the norm? No because I am beyond belief anal when it comes to tunning. And quite frankly if Cobb wasn't releasing atr for this car. The tuning systems available for this platform currently are a joke...